Fig. 1

Principal Component Analysis. A: Positive ion mode (a) D vs Q principal component analysis (PCA) (b) Z vs D principal component analysis (PCA) (c) Z vs Q principal component analysis (PCA). B: Negative ion mode (a) D vs Q principal component analysis (PCA) (b) Z vs D principal component analysis (PCA) (c) Z vs Q principal component analysis (PCA). The horizontal and vertical coordinates PC1 and PC2 in the figure indicate the scores of the first and second ranked principal components respectively, the different coloured scatter points indicate samples from different experimental subgroups, and the ellipses are 95% confidence intervals (95% confidence ellipses cannot be shown when the number of biological replicates is less than 4). (“D” refer to Artemisia sieversiana. “Q” refer to Artemisia annua. “Z” refer to Artemisia wellbyi)